API pricing is the billing model for using an application programming interface. In modern cloud and AI services, it is often metered by requests, compute time, or token volume, so each call has a measurable cost. This makes pricing part of system design: engineers must estimate usage, set limits, and avoid surprise bills.
In cyber security, API pricing matters because cost can become an attack surface. Abuse of public APIs can drive up charges through request flooding, automated scraping, or repeated LLM prompts that consume tokens. Defenders use pricing data to spot anomalies such as sudden spikes in spend, unusual tenant activity, or a compromised key being used at scale. Good controls include authentication, rate limiting, quotas, per-key budgets, and alerting on abnormal spend. Understanding API pricing helps organizations balance capability, availability, and financial risk.